Conventionally, when a printing request is not provided from a client device for a predetermined time period, an image processing apparatus such as a printer generally shifts to a power saving mode appropriately. Such an invention is described in Japanese Laid-Open Patent Publication No. 2009-45860.
Specifically, Japanese Laid-Open Patent Publication No. 2009-45860 describes an image processing apparatus that transmits a response request signal to a specific client device having a predetermined usage amount or more among client devices connected through a network, and shifts to the power saving mode when judging that a reply corresponding to the response request signal is not transmitted from the client device for a predetermined time period.
However, according to the above-described image processing apparatus, since the response request signal is transmitted to the specific client device whose usage amount is merely not less than a predetermined threshold, there is a problem that it is difficult to shift to the power saving mode appropriately in such a case that there is a client device having a large usage amount temporarily in the past.
Specifically, it is generally considered that a client device that is physically apart from an image processing apparatus is unlikely to request a job to the image processing apparatus, however, there was a time when a usage amount of the client device was temporarily increased in the past and if that causes the usage amount to go over the predetermined threshold, a response request signal is also transmitted to the client device.
In addition, when the client device is online, a reply is generally provided corresponding to the response request signal, so that even when the client device is unlikely to request a job to the image processing apparatus at present or in the future, the image processing apparatus can not shift to the power saving mode due to a past temporal increase in the usage amount of the client.